The invention is directed to a gas filtering structure useable in an air handling system to remove foreign materials, as odors, particulates, greases, dust, aerosols, and chemicals from the gas. It is known to use gas purifying material, such as activated carbon, in cartridges having perforated walls for purifying and filtering gas. The activated carbon must be periodically removed from the filtering structure and heated to reactivate the carbon. This requires the disassembly of the filtering structure requiring considerable time and labor. The gas filtering structure of the invention has overcome the disadvantages of the prior art.